1. Field of the Invention
The invention concerns the selective and simultaneous or sequential triggering of high-energy detonators, such as exploding wire detonators or slappers using no sensitive pyrotechnical composition.
2. Description of the Prior Art
There is a felt need, in the field of military charges, to modulate the firing of the charge according to the target, and to do so at the last moment, depending on the position, nature and speed of motion of the target to be reached. This can be obtained by placing several detonators beforehand in the explosive charge, and by selecting, at the last moment, the detonator or detonators to be triggered according to the result to be obtained. This choice must be made when the parameters of the terminal trajectories are known, namely at the instant very shortly before the command to explode the charge.
Furthermore, it is difficult to obtain the almost simultaneous triggering of several detonators.
The value of exploding wire detonators or slappers which do not necessitate the interruption of the pyrotechnical chain in the priming of explosive charges, is known. Furthermore, there are known devices for the commutation of the useful energy in this type of detonator. These are so-called spark-gaps controlled by a high-voltage electrical pulse. The operation of these devices consists in discharging a high-voltage charged capacitor by a control pulse given by a low-voltage/high-voltage pulse transformer. When several priming points are needed, the method consists in using several of these identical circuits. These different points are used, as described earlier, to modulate the firing of the explosive charge.
This method enables the triggering of the detonators according to a given sequence but has certain drawbacks, namely:
the need to use several spark-gaps, one for each point, thus leading to major cost increases in cost and lower dependability;
the difficult of obtaining the precise synchronization of the operation of the spark-gaps to obtain the desired simultaneity in operation with a time difference, called "gitter", of some 10.sup.-7 between the various triggering moments;
the storage of a sufficient quantity of energy for the triggering of each detonator.
The aim of the invention is to cope with these various drawbacks by proposing a selective firing circuit with very fast, simultaneous and selective triggering of a determined number of detonators.